(570i) TEMPO-Oxidized Cellulose Nanofibril Aerogels for Carbon Capture

The IPCC estimates that global surface temperature in the first two decades of the 21^st century was approximately 1˚C higher than the 1850-1900 average, with well-mixed greenhouse gases as the main driver of atmospheric warming. Carbon dioxide (CO₂) is the most abundant greenhouse gas with an annual average atmospheric concentration of 410 ppm, and it is estimated to be responsible for approximately two thirds of the total warming effect of greenhouse gases. CO₂ capture from point sources, such as power or manufacturing plants, could reduce CO₂ emissions when combined with direct air capture (DAC) and storage technologies.

There has been a growing interest in the use of solid CO₂ sorbents for carbon capture due to their potential advantages over liquid adsorbents, such as a reduced energy for regeneration and greater sorption capacity, selectivity, and ease of handling. Commonly investigated sorbents include zeolites, metal-organic frameworks, and amine-functionalized sorbents. Cellulose nanofibril (CNF) aerogels present a more sustainable option for CO₂ capture systems.

We have synthesized a series of TEMPO-oxidized cellulose nanofibril (TCNF) aerogels functionalized with polyethyleneimine and varying graphene oxide loadings for CO₂ capture. The synthesized aerogels were characterized by Fourier transform infrared (FT-IR) spectroscopy, Brunauer-Emmett-Teller (BET) analysis, Scanning Electron Microscopy (SEM), and thermogravimetric analysis (TGA). The pure CO₂ sorption capacity was determined by gravimetric analysis and the working CO₂ adsorption capacity in DAC conditions was obtained from breakthrough measurements in a house-built packed bed column.